It is well known that the feed beam of the rock drill comprises slide guides along which the carriage of the rock drill slides when moving backwards and forwards along the feed beam. Similarly, in telescopic feed beams the parts of the feed beam move relative to one another along corresponding slide guides and the end beam may also move relative to the cradle at the end of the boom along corresponding slide guides. When the weight at the end of the boom is to be reduced, feed beams made of a light metal mixture have been used to reduce their weight. As a consequence of this, it is essential that separate steel slide guides or profiles providing the surface of the slide guide are secured to the feed beams because the wear resistance of light metal is clearly not sufficient in drilling conditions. An arrangement of this kind is known e.g. from Swedish Published Specification 444 346.
The above identified Swedish Published Specification discloses a solution in which the profile of an aluminum feed beam is shaped at the slide guide to be such that in addition to the surfaces of the slide guides at an angle relative to one another, it comprises surfaces narrowing away from the slide guides. The slide guide is made of a flexible steel profile which can be pushed to its place in the cross direction of the feed beam. In this case, the feed beam yields and is able to slide into its place and when it settles into its place, it presses against the surfaces of the feed beam and remains in place by its springback factor. A problem of this solution is that in order to implement cross directional mounting, the steel profile to be used has to be made of a very thin material. As a result of this, it easily works up during use because of damaging and for other reasons, whereby it bends and tends to straighten so that its springback factor weakens and it may fall off. Further, because of securing by the springback factor, the slide profile may slightly move relative to the beam and as a result, the dust between the profile and the feed beam may wear the end beam fast at the same time as the changes of form in the profile will be faster and thus the service life of the feed beam and slide profile will become shorter. Also, in situations in which the slide pieces or the carriage of the rock drill are clamped too tight against the slide guide, it may cause the slide guide to jolt and thus it will be permanently damaged at once.